A true analogy typically provides a clear comparison between two different things based on their functions or characteristics. In this case, option D is the best example of a true analogy.
D. The cell is like a factory; it processes raw materials and produces energy.
This analogy is true because both a cell and a factory take raw materials (nutrients for the cell and raw resources for the factory) and convert them into energy (ATP in the cell and finished products in the factory), highlighting functional similarities between the two.